# Category: Theoretical computer science

Idempotence
Idempotence (UK: /ˌɪdɛmˈpoʊtəns/, US: /ˈaɪdəm-/) is the property of certain operations in mathematics and computer science whereby they can be applied multiple times without changing the result beyond
Rough set
In computer science, a rough set, first described by Polish computer scientist Zdzisław I. Pawlak, is a formal approximation of a crisp set (i.e., conventional set) in terms of a pair of sets which gi
Property testing
In computer science, a property testing algorithm for a decision problem is an algorithm whose query complexity to its input is much smaller than the instance size of the problem. Typically property t
Monge array
In mathematics applied to computer science, Monge arrays, or Monge matrices, are mathematical objects named for their discoverer, the French mathematician Gaspard Monge. An m-by-n matrix is said to be
Configurable modularity
Configurable modularity is a term coined by Raoul de Campo of IBM Research and later expanded on by Nate Edwards of the same organization, denoting the ability to reuse independent components by chang
Gödel Prize
The Gödel Prize is an annual prize for outstanding papers in the area of theoretical computer science, given jointly by the European Association for Theoretical Computer Science (EATCS) and the Associ
Extractor (mathematics)
An -extractor is a bipartite graph with nodes on the left and nodes on the right such that each node on the left has neighbors (on the right), which has the added property thatfor any subset of the le
Tree automaton
A tree automaton is a type of state machine. Tree automata deal with tree structures, rather than the strings of more conventional state machines. The following article deals with branching tree autom
Algorithmic transparency
Algorithmic transparency is the principle that the factors that influence the decisions made by algorithms should be visible, or transparent, to the people who use, regulate, and are affected by syste
Probabilistic bisimulation
In theoretical computer science, probabilistic bisimulation is an extension of the concept of bisimulation for fully probabilistic transition systems first described by and . A discrete probabilistic
Lambda calculus
Lambda calculus (also written as λ-calculus) is a formal system in mathematical logic for expressing computation based on function abstraction and application using variable binding and substitution.
Quantum algorithm
In quantum computing, a quantum algorithm is an algorithm which runs on a realistic model of quantum computation, the most commonly used model being the quantum circuit model of computation. A classic
Postselection
In probability theory, to postselect is to condition a probability space upon the occurrence of a given event. In symbols, once we postselect for an event , the probability of some other event changes
Comp.theory
No description available.
Formal verification
In the context of hardware and software systems, formal verification is the act of proving or disproving the correctness of intended algorithms underlying a system with respect to a certain formal spe
Language Of Temporal Ordering Specification
In computer science Language Of Temporal Ordering Specification (LOTOS) is a formal specification language based on temporal ordering of events. LOTOS is used for communications protocol specification
Representer theorem
For computer science, in statistical learning theory, a representer theorem is any of several related results stating that a minimizer of a regularized empirical risk functional defined over a reprodu
Semigroup action
In algebra and theoretical computer science, an action or act of a semigroup on a set is a rule which associates to each element of the semigroup a transformation of the set in such a way that the pro
Promise theory
Promise Theory, in the context of information science, is a model of voluntary cooperation between individual, autonomous actors or agents who publish their intentions to one another in the form of pr
Recursive definition
In mathematics and computer science, a recursive definition, or inductive definition, is used to define the elements in a set in terms of other elements in the set (Aczel 1977:740ff). Some examples of
Tardiness (scheduling)
In scheduling, tardiness is a measure of a delay in executing certain operations and earliness is a measure of finishing operations before due time. The operations may depend on each other and on the
European Association for Theoretical Computer Science
The European Association for Theoretical Computer Science (EATCS) is an international organization with a European focus, founded in 1972. Its aim is to facilitate the exchange of ideas and results am
Reed–Muller code
Reed–Muller codes are error-correcting codes that are used in wireless communications applications, particularly in deep-space communication. Moreover, the proposed 5G standard relies on the closely r
Turing machine
A Turing machine is a mathematical model of computation describing an abstract machine that manipulates symbols on a strip of tape according to a table of rules. Despite the model's simplicity, it is
Krivine machine
In theoretical computer science, the Krivine machine is an abstract machine (sometimes called virtual machine). As an abstract machine, it shares features with Turing machines and the SECD machine. Th
Chemical computer
A chemical computer, also called a reaction-diffusion computer, Belousov–Zhabotinsky (BZ) computer, or gooware computer, is an unconventional computer based on a semi-solid chemical "soup" where data
ACM Doctoral Dissertation Award
The ACM Doctoral Dissertation Award is awarded annually by the Association for Computing Machinery to the authors of the best doctoral dissertations in computer science and computer engineering. The a
Chaos computing
In theoretical computer science, chaos computing is the idea of using chaotic systems for computation. In particular, chaotic systems can be made to produce all types of logic gates and further allow
Dis-unification (computer science)
Dis-unification, in computer science and logic, is an algorithmic process of solving inequations between symbolic expressions.
Quantum computing
Quantum computing is a type of computation whose operations can harness the phenomena of quantum mechanics, such as superposition, interference, and entanglement. Devices that perform quantum computat
Unrestricted algorithm
An unrestricted algorithm is an algorithm for the computation of a mathematical function that puts no restrictions on the range of the argument or on the precision that may be demanded in the result.
British Colloquium for Theoretical Computer Science
The British Colloquium for Theoretical Computer Science (BCTCS) is an organisation, founded in 1985, that represents the interests of Theoretical Computer Science in the UK, e.g. through representatio
Categorical logic
Categorical logic is the branch of mathematics in which tools and concepts from category theory are applied to the study of mathematical logic. It is also notable for its connections to theoretical co
Angelic non-determinism
In computer science, angelic non-determinism is the execution of a nondeterministic algorithm where particular choices are declared to always favor a desired result, if that result is possible. For ex
Quantum digital signature
A Quantum Digital Signature (QDS) refers to the quantum mechanical equivalent of either a classical digital signature or, more generally, a handwritten signature on a paper document. Like a handwritte
Hub labels
In computer science, hub labels or the hub-labelling algorithm is a method that consumes much fewer resources than the lookup table but is still extremely fast for finding the shortest paths between n
Theory of Computing Systems
Theory of Computing Systems is a peer-reviewed scientific journal published by Springer Verlag. Published since 1967 as Mathematical Systems Theory and since volume 30 in 1997 under its current title,
Profinite word
In mathematics, more precisely in formal language theory, the profinite words are a generalization of the notion of finite words into a complete topological space. This notion allows the use of topolo
Analysis of Boolean functions
In mathematics and theoretical computer science, analysis of Boolean functions is the study of real-valued functions on or (such functions are sometimes known as pseudo-Boolean functions) from a spect
Glossary of quantum computing
This glossary of quantum computing is a list of definitions of terms and concepts used in quantum computing, its sub-disciplines, and related fields. Bacon–Shor_codeis a Subsystem error correcting cod
Corecursion
In computer science, corecursion is a type of operation that is dual to recursion. Whereas recursion works analytically, starting on data further from a base case and breaking it down into smaller dat
Nerode Prize
The EATCS–IPEC Nerode Prize is a theoretical computer science prize awarded for outstanding research in the area of multivariate algorithmics. It is awarded by the European Association for Theoretical
Quantum complexity theory
Quantum complexity theory is the subfield of computational complexity theory that deals with complexity classes defined using quantum computers, a computational model based on quantum mechanics. It st
Safety and liveness properties
Properties of an execution of a computer program —particularly for concurrent and distributed systems— have long been formulated by giving safety properties ("bad things don't happen") and liveness pr
Algorithmic technique
In mathematics and computer science, an algorithmic technique is a general approach for implementing a process or computation.
Quasi-empiricism in mathematics
Quasi-empiricism in mathematics is the attempt in the philosophy of mathematics to direct philosophers' attention to mathematical practice, in particular, relations with physics, social sciences, and
Correctness (computer science)
In theoretical computer science, an algorithm is correct with respect to a specification if it behaves as specified. Best explored is functional correctness, which refers to the input-output behavior
Regular numerical predicate
In computer science and mathematics, more precisely in automata theory, model theory and formal language, a regular numerical predicate is a kind of relation over integers. Regular numerical predicate
Nominal techniques
Nominal techniques in computer science are a range of techniques, based on , for handling names and binding, e.g. in abstract syntax. Research into nominal sets gave rise to nominal terms, a metalangu
Algorithm engineering
Algorithm engineering focuses on the design, analysis, implementation, optimization, profiling and experimental evaluation of computer algorithms, bridging the gap between algorithm theory and practic
Small-bias sample space
In theoretical computer science, a small-bias sample space (also known as -biased sample space, -biased generator, or small-bias probability space) is a probability distribution that fools parity func
Ranked alphabet
In theoretical computer science and formal language theory, a ranked alphabet is a pair of an ordinary alphabet F and a function Arity: F→. Each letter in F has its arity so it can be used to build te
Hindley–Milner type system
A Hindley–Milner (HM) type system is a classical type system for the lambda calculus with parametric polymorphism. It is also known as Damas–Milner or Damas–Hindley–Milner. It was first described by J
Full-employment theorem
In computer science and mathematics, a full employment theorem is a term used, often humorously, to refer to a theorem which states that no algorithm can optimally perform a particular task done by so
API-Calculus
API Calculus is a program that solves calculus problems using operating systems within a device that solves calculus problems. In 1989 the PI- Calculus was created by Robin Milner and was very success
Complexity function
In computer science, the complexity function of a word or string (a finite or infinite sequence of symbols from some alphabet) is the function that counts the number of distinct factors (substrings of
Journal of Automata, Languages and Combinatorics
The Journal of Automata, Languages and Combinatorics (JALC) is a peer-reviewed scientific journal of computer science. It was established in 1965 as the Journal of Information Processing and Cyberneti
Complexity class
In computational complexity theory, a complexity class is a set of computational problems of related resource-based complexity. The two most commonly analyzed resources are time and memory. In general
Recursion (computer science)
In computer science, recursion is a method of solving a computational problem where the solution depends on solutions to smaller instances of the same problem. Recursion solves such recursive problems
Manifold hypothesis
In theoretical computer science and the study of machine learning, the manifold hypothesis is the hypothesis that many high-dimensional data sets that occur in the real world actually lie along low-di
Concurrence (quantum computing)
In quantum information science, the concurrence is a state invariant involving qubits.
Computability in Europe
The Association Computability in Europe (ACiE) is an international organization of mathematicians, logicians, computer scientists, philosophers, theoretical physicists and others interested in new dev
Neighbour-sensing model
The Neighbour-Sensing mathematical model of hyphal growth is a set of interactive computer models that simulate the way fungi hyphae grow in three-dimensional space. The three-dimensional simulation i
Theoretical computer science
Theoretical computer science (TCS) is a subset of general computer science and mathematics that focuses on mathematical aspects of computer science such as the theory of computation, lambda calculus,
Coinduction
In computer science, coinduction is a technique for defining and proving properties of systems of concurrent interacting objects. Coinduction is the mathematical dual to structural induction. Coinduct
Ambient calculus
In computer science, the ambient calculus is a process calculus devised by Luca Cardelli and Andrew D. Gordon in 1998, and used to describe and theorise about concurrent systems that include mobility.
Grammar systems theory
Grammar systems theory is a field of theoretical computer science that studies systems of finite collections of formal grammars generating a formal language. Each grammar works on a string, a so-calle
Tree transducer
In theoretical computer science and formal language theory, a tree transducer (TT) is an abstract machine taking as input a tree, and generating output – generally other trees, but models producing wo
Knowledge Based Software Assistant
The Knowledge Based Software Assistant (KBSA) was a research program funded by the United States Air Force. The goal of the program was to apply concepts from artificial intelligence to the problem of
Bigraph
A bigraph can be modelled as the superposition of a graph (the link graph) and a set of trees (the place graph). Each node of the bigraph is part of a graph and also part of some tree that describes h
Error tolerance (PAC learning)
In PAC learning, error tolerance refers to the ability of an algorithm to learn when the examples received have been corrupted in some way. In fact, this is a very common and important issue since in
Cobham's theorem
Cobham's theorem is a theorem in combinatorics on words that has important connections with number theory, notably transcendental numbers, and automata theory. Informally, the theorem gives the condit
Institution (computer science)
The notion of institution was created by Joseph Goguen and Rod Burstall in the late 1970s, in order to deal with the "population explosion among the logical systems used in computer science". The noti
Knuth's Simpath algorithm
Simpath is an algorithm introduced by Donald Knuth that constructs a zero-suppressed decision diagram (ZDD) representing all simple paths between two vertices in a given graph.
Formal language
In logic, mathematics, computer science, and linguistics, a formal language consists of words whose letters are taken from an alphabet and are well-formed according to a specific set of rules. The alp
Demonic non-determinism
A term which describes the execution of a non-deterministic program where all choices are made in favour of non-termination.
Least-squares spectral analysis
Least-squares spectral analysis (LSSA) is a method of estimating a frequency spectrum, based on a least squares fit of sinusoids to data samples, similar to Fourier analysis. Fourier analysis, the mos
Dynamic Data Driven Applications Systems
Dynamic Data Driven Applications Systems (DDDAS) is a new paradigm whereby the computation and instrumentation aspects of an application system are dynamically integrated in a feed-back control loop,
Institutional model theory
In mathematical logic, institutional model theory generalizes a large portion of first-order model theory to an arbitrary logical system.
Summer School Marktoberdorf
The International Summer School Marktoberdorf is an annual two-week summer school for international computer science and mathematics postgraduate students and other young researchers, held annually si
Pseudorandomness
A pseudorandom sequence of numbers is one that appears to be statistically random, despite having been produced by a completely deterministic and repeatable process.
PEPA
Performance Evaluation Process Algebra (PEPA) is a stochastic process algebra designed for modelling computer and communication systems introduced by Jane Hillston in the 1990s. The language extends c
Occam learning
In computational learning theory, Occam learning is a model of algorithmic learning where the objective of the learner is to output a succinct representation of received training data. This is closely
Motion planning
Motion planning, also path planning (also known as the navigation problem or the piano mover's problem) is a computational problem to find a sequence of valid configurations that moves the object from
Computational learning theory
In computer science, computational learning theory (or just learning theory) is a subfield of artificial intelligence devoted to studying the design and analysis of machine learning algorithms.
Expander mixing lemma
The expander mixing lemma intuitively states that the edges of certain -regular graphs are evenly distributed throughout the graph. In particular, the number of edges between two vertex subsets and is
ACM SIGACT
ACM SIGACT or SIGACT is the Association for Computing Machinery Special Interest Group on Algorithms and Computation Theory, whose purpose is support of research in theoretical computer science. It wa
Algorithmic logic
Algorithmic logic is a calculus of programs that allows the expression of semantic properties of programs by appropriate logical formulas. It provides a framework that enables proving the formulas fro
LogP machine
The LogP machine is a model for parallel computation.It aims at being more practical than the PRAM model while still allowing for easy analysis of computation.The name is not related to the mathematic
Dominance-based rough set approach
The dominance-based rough set approach (DRSA) is an extension of rough set theory for multi-criteria decision analysis (MCDA), introduced by Greco, Matarazzo and Słowiński. The main change compared to
Combinatorial optimization
Combinatorial optimization is a subfield of mathematical optimization that consists of finding an optimal object from a finite set of objects, where the set of feasible solutions is discrete or can be
Lowest common ancestor
In graph theory and computer science, the lowest common ancestor (LCA) (also called least common ancestor) of two nodes v and w in a tree or directed acyclic graph (DAG) T is the lowest (i.e. deepest)
Machine learning in physics
Applying classical methods of machine learning to the study of quantum systems is the focus of an emergent area of physics research. A basic example of this is quantum state tomography, where a quantu
Nominal terms (computer science)
Nominal terms are a metalanguage for embedding object languages with binding constructs into. Intuitively, they may be seen as an extension of first-order terms with support for name binding. Conseque
Quantum capacity
In the theory of quantum communication, the quantum capacity is the highest rate at which quantum information can be communicated over many independent uses of a noisy quantum channel from a sender to
Lulu smoothing
In signal processing, Lulu smoothing is a nonlinear mathematical technique for removing impulsive noise from a data sequence such as a time series. It is a nonlinear equivalent to taking a moving aver
Fundamenta Informaticae
Fundamenta Informaticae is a peer-reviewed scientific journal covering computer science. The editor-in-chief is Damian Niwiński. It was established in 1977 by the Polish Mathematical Society as Series
Sun–Ni law
Within theoretical computer science, Sun–Ni's Law (or Sun and Ni's Law, also known as memory-bounded speedup), is a memory-bounded speedup model which states that as computing power increases the corr
Granular computing
Granular computing (GrC) is an emerging computing paradigm of information processing that concerns the processing of complex information entities called "information granules", which arise in the proc
Interactive computation
In computer science, interactive computation is a mathematical model for computation that involves input/output communication with the external world during computation.
Simulation (computer science)
In theoretical computer science a simulation is a relation between state transition systems associating systems that behave in the same way in the sense that one system simulates the other. Intuitivel
Bird–Meertens formalism
The Bird–Meertens formalism (BMF) is a calculus for deriving programs from specifications (in a functional-programming setting) by a process of equational reasoning. It was devised by Richard Bird and
Bio-inspired computing
Bio-inspired computing, short for biologically inspired computing, is a field of study which seeks to solve computer science problems using models of biology. It relates to connectionism, social behav
Computational irreducibility
Computational irreducibility is one of the main ideas proposed by Stephen Wolfram in his 2002 book A New Kind of Science, although the concept goes back to studies from the 1980s.
Tree (automata theory)
In automata theory, a tree is a particular way of representing a tree structure as sequences of natural numbers. For example, each node of the tree is a word over set of natural numbers, which helps t
Π-calculus
In theoretical computer science, the π-calculus (or pi-calculus) is a process calculus. The π-calculus allows channel names to be communicated along the channels themselves, and in this way it is able
Scientific community metaphor
In computer science, the scientific community metaphor is a metaphor used to aid understanding scientific communities. The first publications on the scientific community metaphor in 1981 and 1982 invo
Quantum threshold theorem
In quantum computing, the quantum threshold theorem (or quantum fault-tolerance theorem) states that a quantum computer with a physical error rate below a certain threshold can, through application of
Circuit Value Problem
The Circuit Value Problem (or Circuit Evaluation Problem) is the computational problem of computing the output of a given Boolean circuit on a given input. The problem is complete for P under uniform
Indirect self-reference
Indirect self-reference describes an object referring to itself indirectly. For example, define the function f such that f(x) = x(x). Any function passed as an argument to f is invoked with itself as
Bisimulation
In theoretical computer science a bisimulation is a binary relation between state transition systems, associating systems that behave in the same way in that one system simulates the other and vice ve
Computational problem
In theoretical computer science, a computational problem is a problem that may be solved by an algorithm. For example, the problem of factoring "Given a positive integer n, find a nontrivial prime fac
Description number
Description numbers are numbers that arise in the theory of Turing machines. They are very similar to Gödel numbers, and are also occasionally called "Gödel numbers" in the literature. Given some univ
Pattern language (formal languages)
In theoretical computer science, a pattern language is a formal language that can be defined as the set of all particular instances of a string of constants and variables. Pattern Languages were intro
Formal methods
In computer science, formal methods are mathematically rigorous techniques for the specification, development, and verification of software and hardware systems. The use of formal methods for software
Knuth Prize
The Donald E. Knuth Prize is a prize for outstanding contributions to the foundations of computer science, named after the American computer scientist Donald E. Knuth.
Transcriptor
A transcriptor is a transistor-like device composed of DNA and RNA rather than a semiconducting material such as silicon. Prior to its invention in 2013, the transcriptor was considered an important c
Weakest precondition
No description available.
Level ancestor problem
In graph theory and theoretical computer science, the level ancestor problem is the problem of preprocessing a given rooted tree T into a data structure that can determine the ancestor of a given node
Natural computing
Natural computing, also called natural computation, is a terminology introduced to encompass three classes of methods: 1) those that take inspiration from nature for the development of novel problem-s
Spintronics
Spintronics (a portmanteau meaning spin transport electronics), also known as spin electronics, is the study of the intrinsic spin of the electron and its associated magnetic moment, in addition to it
French Institute for Research in Computer Science and Automation
The National Institute for Research in Digital Science and Technology (Inria) (French: Institut national de recherche en sciences et technologies du numérique) is a French national research institutio
Flajolet Lecture Prize
The Philippe Flajolet Lecture Prize is awarded to for contributions to analytic combinatorics and analysis of algorithms, in the fields of theoretical computer science. This prize is named in memory o
Quantum machine learning
Quantum machine learning is the integration of quantum algorithms within machine learning programs. The most common use of the term refers to machine learning algorithms for the analysis of classical
Automated reasoning
In computer science, in particular in knowledge representation and reasoning and metalogic, the area of automated reasoning is dedicated to understanding different aspects of reasoning. The study of a
Exact cover
In the mathematical field of combinatorics, given a collection S of subsets of a set X, an exact cover is a subcollection S* of S such that each element in X is contained in exactly one subset in S*.
Learning augmented algorithm
A learning augmented algorithm is an algorithm that can make use of a prediction to improve its performance.Whereas in regular algorithms just the problem instance is inputted, learning augmented algo
Bridging model
In computer science, a bridging model is an abstract model of a computer which provides a between the physical implementation of the machine and the abstraction available to a programmer of that machi
Calculating Space
Calculating Space (German: Rechnender Raum) is Konrad Zuse's 1969 book on automata theory. He proposed that all processes in the universe are computational. This view is known today as the simulation
Computation
Computation is any type of arithmetic or non-arithmetic calculation that follows a well-defined model (e.g., an algorithm). Mechanical or electronic devices (or, historically, people) that perform com
Algorithm
In mathematics and computer science, an algorithm (/ˈælɡərɪðəm/) is a finite sequence of rigorous instructions, typically used to solve a class of specific problems or to perform a computation. Algori